Clamp



April 11, 1939. R. R. FREDERICK CLAMP .2 Sheets-Sheet 1 Filed 'Jan. 21,1937 INVEN'L 01;.

ATTORNEY.

RlRJ-re derick.

BY D 2 April 11, 1939. R. R. FREDERICK CLAMP Filed Jan. 21, 1937 2Sheets-Sheet 2 A. R. Frederick. INVENTOR.

BY )y ATTORNEY.

Patented Apr. 11,1939

UNITED STATES PATENT OFFICE CLADIP Application January 21, 1937, SerialNo. 121,534

6 Claims.

This invention relates to an improved clamp and particularly to a clampfor use in gripping and handling large, comparatively thin sheets ofsheeted material, such as felt base floor covering, linoleum, rubber andthe like.

The clamp is especially suitable for pulling sheets of printed felt baseor linoleum into the heaters or drying racks. The clamps heretofore usedrequired a relatively large space or opening between the various dryingracks in order that the clamp fastened to the sheet material could bepulled through the racks. A conservative estimate of the space betweenthe rack levels would be approximately 3 or 4 inches. However, with theclamp, which will be hereinafter described as my invention, the spacebetween the rack levels can be reduced inasmuch as the thickness of theclamp is substantially less than that of previously used clamps. Theover-all thickness ofmy clamp may be as small as 1 inch, and theresults. accomplished by the clamp will be equally as satisfactory asheretofore obtained with other clamps. Thus through the use of my clamp,the number of racks in the heater can be increased thereby increasingthe heater capacity.

It is, therefore, among the objects of my invention to provide a clampwhich is relatively thin and can be used in pulling sheet materials intodrying racks which are spaced less distance apart than the drying racksnow found in. heaters used in drying sheet materials.

Another object of my invention is to provide a clamp which is of simpleand rugged construction adapted to withstand the abuses to which clampsare ordinarily subjected to in pulling heavy sheet materials. The clampis simple in construction in that it has relatively few moving parts andin being constructed substantially throughout of metal and leather, theruggedness of the clamp will be quite apparent.

Another object of my invention is to provide a clamp which takes andmaintains a secure grip to on the sheet material being handled and atthe same time willengage only a very'narrow portion of the sheetmaterial. The clamps previously used required relatively large grippingareas in order to acquire a firm grip or hold on the sheet material,thereby causing considerable damage to the material. The clamp describedas my invention engages a very narrow edge of the sheet ma.- terial,approximately three-eighths of an inch, thus eliminating the necessityof re-processing or scrapping of large quantities of the processed sheetmaterial which were previously damaged by the larger and vwider clamps.

A further object of my invention is. to provide a clamp which willengage the edge of the entire width ofthe sheet material therebyacquiring a more secure grip on the sheet than has heretofore beenobtained with clamps that had spaced clamping elements. It is obviousthat if a clamp should become loosened from the sheet as the material isbeing pulled into the drying racks,

is relatively simple to operate and light in weight thereby eliminatingextra labor ordinarily expended .in handling the more complicated andheavy clamps. Previously, the large and heavier clamps were cumbersomeand bulky and imposed an unnecessary burden upon the men who handled theclamps. However, through the use of my clamp, this unnecessary labor andexpenditure of energy is eliminated.

My invention possesses other objects and features of advantage, some ofwhich, with the ones indicated above, will be apparent as my inventionwill be discussed in detail. It is understood that I do not limit myselfto the disclosure of species of my invention, as I may apply varyingembodiments thereof within the scope of the claims.

Referring to the accompanying drawings:

Fig. 1 is a plan view of my clamp.

Fig. 2'is a fragmentary perspective of the end of the clamp.

Fig. 3 is a perspective of the handle used to operate the clamp.

Fig. 4 is a sectional view of sheet material extending through the slotsof the fixed tube and the rotatable circular element and into the grooveof the core.

Fig. 5 is a perspective viewof my clamp, and shows the sheet materialextending into the clamp.

Fig. 6 is a side view of a modified inner tubing which can be used inplace of the inner element disclosed in Fig. 4.

In terms of broad discussion, the clamp embodying my invention comprisesa pair of substantially concentric elements having a longi tudinal slotand groove, respectively, extending substantially throughout therespective lengths of the elements. The outer tube is fixed securely toa suitable holding means. The inner grooved element is adapted to rotatewithin the outer tube and any sheet material which is inserted throughthe openings of the concentric elements will be clamped securely betweenthe walls of the inner and the outer elements. a

In greater detail and referring particularly to the drawings, the clampembodying my invention comprises a pair of concentric tubings orcylinders 2 and 3 having slots extending longitudinally substantiallythrough the length of the tubes. The slots are best illustrated in Fig.4. The inner tube 3 has a rounded or tapered portion, as noted at 5, atone of the edge portions of the slot. The rounded or tapered portion isnecessary to pre-' vent a shearing action of the sheeted material 2|,

as the inner tube 3 is rotated within in tube 2.

A core 4 having a longitudinal groove 6 extending substantiallythroughoutits length is fixed within the tube 3. The core may be made ofwood, metal or any other suitable material adapted to withstand roughtreatment, but which, at the same time, is: comparatively light inweight so that. the weight of the clamp is not unduly increased.

A substantially T-shaped metallic element or holder is secured to theouter tube 2, and flexible straps 8 are, in turn, fixed to the stem ofthe T-shaped element as illustrated in Figs. 1, 4 and 5. A harness 20unites the straps 8 and is brought together at IE to form a reinforcedpoint for the insertion of the hook used in pulling the sheet materialthrough the heaters.

Handles H! are fastened at each end of tube 3 which enables the innertube and core to be rotated to open and close the clamp. The handle, asshown in Fig. 5 is in a closed position 'and is held locked in placethrough the mediuln of a locking pin I9 which slides in groove !3 and isadapted to penetrate the opening ll of the handle. A handle for theoperation of the clamp is not necessary at each end since the clamp canreadily be operated by one operator, but for convenience in operation, ahandle is shown at both ends. In actual use, it is preferable to movethe handles at each end of the clamp simultaneously which will relievean unnecessary twisting or torque action upon the inner tube. In orderto remove the clamp from the sheet, the operation can be handled verysatisfactorily with one handle, after the locking pins at each handlehave been released since, in releasing the clamp, it is mereiy aquestion of releasing the pressure previously exerted on the edge of thesheet.

A typical handle, especially suitable for use in operating the describedclamp, is shown in. Fig. 3, however, this handle is merely illustrativeand is not to be construed as the only type handle adapted to theinvention. The elements l3 and M are set screws which enable the handleto be loosened, fastened or adjusted in a very short time. In order tomake rapid adjustments of the handle to keep the slotted openings oftubes 2 and 3 in proper alignment which is necessary to receive thesheet material, it has been found that roughened surfaces, as indicatedat H and I2, are especially suitable for rapid and accurate adjustments.This feature is particularly important in cases where the clamp must beadjusted to compensate for different gauges of the processed sheetmaterial, or when, for any other \reason, there is need for a tighter ormore secure gripping action upon the sheet. It is possible that thegripping action of the clamp may be decreased after being used for aperiod of time due primarily to normal wear and tear upon the variousclamp elements, but the roughened [1 surfaces make it possible that theoriginal gripping action may again be obtained by merely adjusting thehandle. The roughened surfaces may be fine groovings, threads orequivalent markings, but it is understood that the invention is in noway limited by these features.

In operating the clamp, the slotted openings of the concentric tubes arebrought into alignment as shown in Fig. 4. The handle IE! is shown inthe open position in this figure. The sheet material 2|, ordinarilysupported on a table 22, is entered through the opening 9 of tube 2,then through the opening of tube 3 and finally into the groove 6 ofelement 4. The depth of the groove 6 will serve as the limiting means asto the amount of material inserted into the clamp and which will besubjected to the clamping action. The handle I0 is then pulled from theposition indicated in Fig. 4 to the closed position as indicated in Fig.5. As the handle 10 is pulled toward the closed position, the slottedtube 3 and core 4 are turned and the sheet material will be clampedbetween the inner walls of tube 2 and the walls of tube 3. Inasmuch astube 3 has a rounded or tapered edge as indicated by the numeral 5, noshearing of the sheet material will occur. The action will tend to holdthe sheet firmly and the grip will not be loosened except when thehandle is brought back to the open position shown in Fig. 4. After thehandle has been brought into the closed position shown in Fig. 5, thekey I9 is slid forward through the opening I! of the handle and thegripping action cannot be lessened until the key is moved back and thehandle released.

A modified form of the inner tubing is shown in Fig. 6. The modifiedform eliminates the use of the central core 4. In the modified form theinner tube does not have a longitudinally extending slot as disclosed intube 3, but has a longitudinally extending groove 24 extendingsubstantially through the length of the tube 23. The modified form ismerely substituted in place of the grooved circular element and can beused with equal adaptation as the combination slotted tube 3 and groovedcore 4, and is, therefore, included within the scope of the presentinvention.

The sheet material is inserted through the slot of the outer tube, andthence to the bottom of the groove 24 of tube 23. The bottom of groove24 will limit the amount of sheet material which can be inserted intothe clamp. When the tube 23 is turned through the medium of the handles,the gripping action upon the sheet material will occur in the samemanner as described above.

The metallic elements, as the tubings and the T-shaped element, arepreferably made of any comparatively light weight metals so that theclamp will be relatively convenient to handle. This light weight featureis important since such clamps are being constantly handled in pullingsheet materials into and out of heaters; however, if the question ofweight and strength is not essential, any material can be used. Itshould be understood that the drawings are merely illustrative and donot pretend to give exact proportions. Furthermore, the said drawingsand description are illustrative of preferred constructions; however, itis clearly evident that the modifications may be further altered by oneskilled in the art without departing from the spirit and scope of theinvention.

I claim:

1. A clamp for gripping the edge of a sheet material which comprises aslotted tube securely fixed to a holder, a grooved circular elementineluding a slotted tube and a grooved core placed within saidfirst-named slotted tube, and substantially concentric thereto, andmeans to move said grooved circular element with relation to the fixedslotted tube.

2. A clamp for gripping the edge of a sheet material as defined in claim1, in which the edge of the grooved circular element is rounded.

3. A clamp for gripping the edge of a sheet material as defined in claim1, in which the edge of the grooved circular element is tapered.

4. A clamp for gripping the edge of a sheet material which comprises aslotted metallic tube securely fixed to a holder, a grooved circularelement including a slotted member and a grooved core placed within theslotted tube and substantially concentric thereto, said slot of the tubeand groove of the circular element being in alignment to receive theedge of a sheet material, means to move the grooved element to move theslot and groove out of alignment to a closed position, thereby clampingthe sheet material, and

means to lock the clamp in the closed position.

5. A clamp for gripping the edge of a sheet material as defined in claim4, in which the edge of the grooved element is rounded.

6. A clamp for gripping the edge of a sheet material as defined in claim4, in which the edge of the grooved element is tapered.

ROBERT R. FREDERICK.

